#include <iostream>
using namespace std;

double a,b,c,m;
double doMax(double x, double y, double z) {
    double val;
    double m1 = max(x, y);
    return max(m1, z);
}

int main() {
    cin >> a >> b >> c;
    m = doMax(a, b, c) / (doMax(a+b, b, c) * doMax(a,b,b+c));
    printf("%.3f", m);
    return 0;
}